Transformation apparatus, decision apparatus, quantum computation apparatus, and quantum machine learning system

First, a dual basis B− of B of modulo N is obtained by classical computation. Next, quantum computation is performed using the periodicity of a point sequence included in a sum set of sets obtained by parallel translation of a lattice L(B) by integral multiples of t for a plurality of integers, and an n-dimensional rj=(rj1, . . . , rjn) and rj0 are obtained for j=1, . . . , m. Subsequently, by classical computation, the closest vector rj(c)=(rj1(c), . . . , rjn(c))∈L(B−) of the n-dimensional vector rj, and the difference vector rj(d)=rj−rj(c)=(rj1(d), . . . , rjn(d)) corresponding to rj(c) are obtained.